ROCK 3A v1.3 Maskroom OK, NO Boot, NO UART tested power, UART and SD on another board

[jaysonsantos]

I have a ROCK 3A that reaches Maskrom/recovery but will not boot any Radxa or Armbian SD image and produces no useful UART output. UART is configured per Radxa docs at 1500000 8N1 on the debug header, and the exact same adapter/host/settings work on another ROCK 3A. There is no eMMC and no NVMe installed. I also tried resetting/loading SPI via Maskrom using rkdeveloptool db rk356x_spl_loader_ddr1056_v1.12.109_no_check_todly.bin, then loading Radxa’s rock-3a-spi-image-gef9f6b1caad.img. Radxa’s ROCK 3A loader directory contains the matching SPI artifacts, including rock-3a-spi-image-gef9f6b1caad.img, rock-3a-idbloader-gef9f6b1caad.img, and rock-3a-u-boot-gef9f6b1caad.itb, along with RK356x SPL loader binaries. Looking for guidance on whether this points to SPI/SPL/DDR init or a board hardware fault.

[Werner]

7 hours ago, jaysonsantos said:

produces no useful UART output.

elaborate. 

If there is only garbage output your usb uart adapter may not be able to handle this speed. Example would be CP2102 which outputs garbage instead of gracefully failing when "overclocked".